A corpora



R. M. HOPKINS.

SIGNAL TRANSMITTER.

APPLICATION man OCT. 1p. I919.

Patented Feb. 14, 1922.

1,406,865. Lmz 715ml mm ATTORNEY.

- I N VEN TOR. Wlu.

uurreos 'ra'iras PA renT orricsp RICHABD IVE. HOPKINS, O1? RUTHERFORD, NEW JERSEY, ASSIGNOR 'IO AMERICAN DISTRICT TELEGRAIEH COMPANY, OF JERSEY CITY, NEW

DION OF NEW JERSEY.

JEESEY, A CORPORA- SIGNAL rnansrirrirnii.

Specification of Letters Patent. Patentd F b 14 1922 Application filed October 10, 1919. Serial No. 329,730.

To all whom it may concern:

Be it known that I, RICHARD M. Horiim s, acitizen of the United States of America, and resident of Rutherford, county of Bergen, and State of New Jersey, have invented improvements in Signal "lransmitters, of which the following is a specification.

My invention relatesto improvements in signal transmitters, particularly that type hereof employed especially in transmitters of the call-box type, which operate both by breaking and closing a line circuit, and by closing and breaking a groundreturn circuit. In the art, such transmitters arecommonly termed lvlcC-ulloh transmitters. In the types of McGulloh transmitters most commonly used, two signal. wheels, With corresponding contact springs, are employed, ne signal wheel, with its corresponding conta ctsprings, being empl yedi or breaking and closing the line circuit, the other signal wheel and its correspondlng contact springs,

being employed for closing and breaking the ground connection; both signal wheels being commonly n'iounted-upon the same rotating shaft. In the construction embodying my present invention, however, one signal. wheel onl is employed, from which tact, and from the simplified arrangement of contact springs employed, much simplification results. My invention consists in a novel arrangement of contact springs in connection with a single signal wheel, as hereinafter described and particularlypointed out in the appended claims.

The object of my invention is to simplify signal transmitters of the type referred to.

I will now proceed to describe my invention with reference to the accompanying drawings, and will then point out the novel "features in claims.

In said. drawings:

Figure 1 is a diagrammatic viewillustrative oi the arrangement of contact springs in connection with the signal wheel and circuits;

Figure 2 is a face view of the transmit;

ter, the enclosing case being omitted;

is a side view of the transmit- The general construction, as so far de understood that when the handle 3 is pulled a down and then released, motion is communicated. through the gear train to the cam 5 and also to the signal wheel 6. s

T designates a contact spring or pen as it is termed in the art,-normally out of contact with the teeth of wheel 6, but adapted to make. contactiwith the teeth of said wheel as the latter pass its tip. As appears from l igure 1, pen 7 is connected by conductors 8 v and 9 to an external circuit connection 10 (which one terminalxof the line-circuit). The wheel 6 itself is in electrical connection with the frame of the apparatus, and therefore with ground; 11 (Figures 1 and 2) being a ground connection. Obviously, circuit will be completed from 10 through 9, 8 and 7, to ground, only when pen 7 is in contact with a teeth of signal wheel 6. I

12, 13 and 14-. are other contact springs, of whicl 12 is arranged to be actuated by the teeth of signal wheel 6, and, when raised by one of said teeth, is caused to be elevated "from spring 18, which spring 18 thereupon conductors S and 9, with line terminal 10. Spring 14 is connected with another line terminal'15.

' In the particular construction shown, the contact springs 7, 12, 13 and 1 1, arev all mounted upon a movable member 16, pivoted at 16 and provided with a toe 1G" adapted to be engaged by cam5, in such manner that while normally the pens 7 and 12 are clear of the teeth of wheel 6. yet seen after wheel 6 begins to rotate, cam 0 moves carrier 16 to bring springs 7 and 12 into the path of the teeth of wheel 6. This, however, is a more feature of the particular transmitter and cam are a mere feature of the particular transmitter indicated in the drawings, and have nothing to do with the present invention.

According to the present invention, in the operation of the transmitter the teeth of wheel 6 successively engage spring 12, thereby lifting said spring away from spring 13, and permitting said spring 13, by its natural resilience, to separate from spring 14, thereby breaking the line circuit, of which 10 and 15 are terminals, as previously explained. As soon as a tooth oi wheel 6 has passed beyond the top oi spring 12, the latter drops, by its natural resilience, again bringing together springs 13 and 14, and so closing the line circuit so far as this transmitter is concerned. The length of spring 7 is such that when springs 13 and 14 are so in contact during the spaces between teeth of .wheel 6, the tip of pen 7 engages a tooth of the wheel 6, so completing a ground connection; that is to say the relation between the lengths of pens 7 and 12, with respect to the spacing of the teeth of the signal wheel, is such that contact of ground pen 7 with a tooth oi the signal wheel occurs while pen 12 is out of engagement with any tooth oil the signal wheel; and, conversely, engagement of any tooth of the signal wheel with pen 12 occurs when pen 7 is not in engagement with any tooth of the signal wheel. Of course there are periods, corresponding to the spaces between tooth groups of the signal wheel, when neither pen 7 nor pen 12 is engaged by any tooth oi the signal wheel.

It will be seen that by causing both the ground pen 7 and the line pen 12, to coact with the teeth of the same signal wheel, and by so arranging these pens that coaction of each of said pens 7 and 12 with a tooth of that signal wheel occurs while the other of said pensis not in engagement with any tooth oi that signal wheel, I eli'ect breakage of the line circuit by the one contact device, and closing of the ground connection by the other contact device, without mutual interference by either contact device with the action of the other.

In transmitters such as heretofore employed for McCulloh operation, and employing two separate signal wheels, it is commonly necessaryto insulate one wheel from the other; by employing a single signal wheel for both the line contact and the i les,

tween the wheels is eliminated, which in turn eliminates various other parts, and furthermore makes the assembly and adjustment of the required parts much more easy, and reduces many sources of possible trouble; moreover, the shape and arrangement of.

this spring as herein illustrated is much simpler than that in the former boxes referred to; for example, all of the contact springs of the present invention may be in one plane, whereas in the double wheel arrangement of former McCulloh boxes, the contact springs for the one signal wheel must commonly be in a planeseparate from that in which contact springs of the other wheel are located. The wiring is also much simplified.

It is apparent that instead of pen 7 making electrical contact with the teeth of the signal wheel, this pen may actuate other contact springs, just as pen 12 actuates contact springs 13 andl l. This is illustrated in Figure 5, wherein the pen is designated by numeral 7?, the contact springs which it actuates being designated by 20 and 21. This arrangement is the mere equivalent of the arrangement wherein pen 7 makes electrical contact with wheel 6.

lVh-at I claim. is:

1. A signal transmitter comprising a single toothed signal wheel, and means for driving same, in combination with two separate contact devices arranged to be engaged by the teeth of said signal wheel, oneof said contact devices comprising an actuating element by engagement of which with the teeth of said signal wheel that contact device is operated, the other ofsaid contact devices arranged to engage said teeth during-periods when the actuating element of the first mentioned contact device is between teeth of said signal wheel and is not being actuated by said teeth.

2. A signal transmitter such as described comprising a toothed signal wheel, such as 6, and means for driving the same, in combination with two separate contact devices, such as 7 and 12, 131 l respectively, arranged to coact with said signal wheel, the member 7 arranged to be engaged by the teeth of said signal wheel during periods when the member 12 is not engaged by said teeth, and vice versa. 1

Intestimony whereof Ihave signed this specification in the presence of two subscribing witnesses.

RICHARD M. nornms. lVitnesses IRWIN J. STURMWALD, H. M. MARBLE,- 

